As ww has already pointed out, the spare nature of your post does not help the monks here know how to be helpful. For example:

What is a '"bulls-eye" graph'? How do characters like '.', '+', '*', and '#' map to underlying values? Can you provide us with an example dataset and what the associated chart would look like (wrapped in <code> tags)?

How much experience with Perl do you have? Is this your first task ever? Are you expert in another language, and just unfamiliar with Perl syntax?

Is this homework? Is this maintaining some esoteric script left by a former employee? Is this a random assignment from a higher up who heard that this Perl thing is pretty useful? Have terrorists kidnapped your daughter, demanding code in exchange for her safe release? Context is important in terms of what resources will be most useful for you in the long run.